Most interfaces have a pad button on them to drop the input gain to -20 db or close to that, to keep it from clipping. Or if your using a separate mic pre then hit the pad button on that instead.

^ ... Or sometimes there's just a switch on the mic itself. As long as it won't clip at the preamp you're good.

When 2 mics are basically the same distance away from the speaker, they are in phase. The only problem is polarity. Unfortunately not a lot of people (the guy in the video included) seem to know the difference. You can switch polarity (and not the phase) on many desks and also on DAW channels by 180 degrees, which means nothing else than mirror the waveform or turning a pluse into a minus. In the video the polarity is ok because the signal doesn't get quieter or hollow when he brings up the second mic' s fader.

Into an interface or mixer

your ass

Two preamps and then record each to its own track.

You can get similar results with equalizer software on your computer. I’m assuming you’re recording into an audio interface?

If you compare it to something like a Boogie or an amp on the more American side of the voicing scale. The Marshall can have a lot less bass in comparison. Think about how massive and fat a Dual Rectifier, 5150, or a Mark Series amp all sound.

Without the deep switch those old jcm2000s sound very thin and buzzy, you have to crank the bass up. Even the new DSL100HR won't sound like a 5150 or anything.

yes really

yes they do🥹